Table 10

Cost parameters included in the sensitivity analysis

Parameter

% Variation relative to base-case

Remark

Minimum

Maximum

Fixed capital investment

0.7

1.3

A range of +/- 30% was considered sufficient to cover uncertainties in capital cost.

Cost of biomass

0.6

1.7

A range of -40% to +70% approximates to the 15th and 85th percentiles obtained in the survey of EU cost estimates for softwood and straw.

Enzymes

0.5

1.5

A range of +/- 50% was considered reasonable given the uncertainties in the costs of enzyme production.

Cost of ethanol

0.3

1.85

The minimum -70% reflects the price of ethanol valued on an energy basis with an oil price of US$40 barrel^-1. The maximum +85% reflects ethanol valued on a volume basis plus subsidy, assuming an oil price of US$150 barrel^-1.

Solid fuel revenue

0.7

1.3

A range of +/- 30% was considered sufficient to cover uncertainties in the retail price of solid fuel.

Distribution cost

0.7

1.3

A range of +/- 30% was considered sufficient to cover uncertainties in distribution cost.

Effective discount rate

1

2

A discount rate range of 7–30% was considered sufficient to cover uncertainties in how a plant may be financed.

Slade et al. Biotechnology for Biofuels 2009 2:3   doi:10.1186/1754-6834-2-3